Pulverized-fuel mixer



Aug. 14, 192s. y

A. A. WICKLAND PULVERIZED FUEL MIXER Filed Dec. 26, 1925 pulverized fuelmixers wherein the pulver Patented Aug. 14, 192e.

1PATENT oFFlcE.

ALGOT WICKLAND, F CHICAGO, ILLINOIS.

PULVERIZED-FUEL MIXER.

Application led December 26, 1923. Serial No. 682,614. A

.l My invention relates to 1m rovements 1n ized fuel is mixed with airin the required proportion so as to secure a thorough and completemixture of the two ingredients so as to burn most efficiently.

Another object of my invention is to pro- 1 vvide means wherein allportions of the charge will be substantially evenly and uniformly mixed,and wherein the portion of the mixer most closely adjacent the furnaceis protected from excessive heat.

Another object of my invention is to provide means for deiiecting theiiow of mixed fuel and air 'discharged from themixer in the desireddirection.

The invention has among its other objects the production of a device ofthe kind described which will be of simple, convenient, economicalconstruction, reliable and satisfactory to use wherever foundapplicable.

Many other objects and advantages of the construction Lherein shown anddescribed will be obviousv to those skilled ,in the art to which thisinvention 'appertains `from the disclosures herein given.

To this end my invention consists of the novel construction,arrangementand combination of parts shown and ldescribed in the speciiica-tion andmore particularly pointed out in the claims.

In the drawings wherein like reference characters indicate like orcorrespondingu parts.

Fig. 1 is a vertical sectionalA View taken through my device);

Fig. 2 is a transverse view taken substantially on a line 2-2 of Fig. 1;and

Fig. 3 is a transverse cross-section taken parallel to that shown inFig. 2, and taken on the line 3 3 of Fig. 1. r

In the drawings, wherein I have illustrat-ed the preferred embodiment ofmy invention there is. shown a mixer comprising an annular orcylindrical member 1 having an end closure plate 2 atone end thereof.

Intermediate the ends of the member 1 there is arranged a sleeve havinga tapered portion 3 engaging the inner Wall of the portion 1 at thelarge endi and extending outwardly axially of the member 1 as at 4, theouter end of the portion 4 bein open and forming the discharge outletFor the pulverized fuel and air.

The chamber 5 within the shell 1 has an intake 6 arranged tangentiallythereinto and through which the pulverized fuel and air enter. Theenteringmixture is under pressure and travels at considerable velocityso that it travels within the chamber in a spiral path'substantially asset forth in my copendmg application, Serial Number 655,404, and thencedischarges through the Outlet at the outer end of the portion 4.

An extension part is arranged at the outer end of the part 1, thisextension having a tapered portion 7 merging into alongitudinallyextending cylindrical portion 8 terminating substantiallyat the end of the portion 4 of the sleeve and thence extended obliquelyinwardly to provide a flange 9 hav-v ing a central opening or dischargeoutlet 10 thereat substantially of the same size as the Idischargeopening through the sleeve 4 and slightly therebeyond.

The large end of the. extension member is secured to the end of the part1 as hereinbefore described and forms an annular chamber 11 with theouter surface of the sleeve member. An air intake 12 is arranged toenter the chamber 11 tangentially thereof as shown and spirals throughthe chamber toward its outlet, the direction of travel of the airthrough the chamber 11 being in reverse direction to the direction ofspiral travel through the chamber 5, as indicated by the arrows in Figs.2 and 3. Y

The inner edge of the liange 9 extends outwardly beyond the adjacent end6 of the -tubular part 4 and a plurality or series of ribs 13 arearranged inV circumferentially spaced relationabout the discharge end oftheextension chamber, said ribs being preferably spiral and extendinglongitudinally inwardly from the flange 9 and of substantially the sameheight as the width of said ange and enga ng and supporting the portion4 of the-s eeve` l It is apparent that any air admitted through the port12 enters the chamber and passes outwardly thereof through the channelsformed between the adjacent ribs and the outer wall of the tubular part4 with which they contact. l

In order to supply additional air to the carbureted mixture admittedthrough the intake 6 a tapered pipe 15 extends axially through the endwall 2 as shown in Fig. 1, the inner end/of said pipe being open to forman outlet 16 and the side wall of said pipe having apertures or openn 17cir cumferentially spaced adjacent t e outlet end 16.

A valve 18 preferably in the shape of a cone is arranged to move axiallythrough the chamber 5 and to seat against the discharge outlet 16 tocontrol passage of air therethrough. l

Bearings 19 and 20 may be provided to support the valve stem, thebearing 20 also acting as a limiting stop to prevent excess movement ofthe valve. Should the valve bc closed, the air passing through the pipe15 will escape radially outwar ly through the perforations 17substantially transversely to the mixture flowing through the chamber 5and co-mingle therewith so as to eiliciently mix the same.

The pulverized fuel enters through the intake 6 at the rear of the mixerand tangentially thereof. This fuel, enteringk at a rather high velocityis mixed with air so that as it swirls through the chamber the heavierparticles, which in the present instance is coal, will be thrownoutwardly to cause a segregation of the coal particles, collectin at theperiphery of the inside of the cham er and forming a ihn of powderedfuel, which will pass through the mixer in the form of a spiral. If thissegregating action is complete it is highly concelvable that the centerof the chamber 5 is substantially free of coal articles since they areall thrown outward y.

To obtain a more thorough mixture of the fuel and air in the chamber 5the secondary air inlet isfprovided and terminates intermediate the endsof the chamber. The valve or deflector 18-causes the secondary air to bcdeflected or thrown outwardly substantially transversely to thedirection of travel 'of the air and coal articles swirling through thechamber and tlgus tends to effect a more thorough ymixture of the sameand break up the film. Even when the valve is in its y,closed positionas shown in full lines, the

secondary air will escape radially outwardly through the a ertures 17and accomplish the same result a though to a lesser degree.

The valve 18 may be arranged to deflect the mixture at any pointintermediate the discharge ends of the parts 15 and 4, as shown indotted lines. The auxiliary air admitted through the intake 12 travelsinfthe opposite direction to the mixture admitted through the inlet 6, andwhen leaving the mixer tends to counteract the whirling motion of themixture. The spirally arranged ribs which are in line with the spiralmovement of the auxiliary air increase the counteract-ing effect justdescribed. This auxiliary air will act to form an exterior film aboutthe core of carbureted mixture discharged through the sleeve and thusrender the same more efficient for combustion within the furnaceadjacent thereto.

Another object of the addition of the auxiliary air 1s to cool theexterior of the mixer and prevent excessive heat radiated from thefurnace from reaching the sleeve 4.

In order to deflect the flow of mixture discharged through the nozzle orsleeve 4, a shield 14 may be arranged for closing a plurality ofadjacent spaces between the ribs 1S as shown, so that onl the uncoveredspaces will permit the auxlliary air to flow therethrough. This shieldis preferably of arcuate radial cross-section and is of any suitablearcuate length, as for instance semicircular, as indicated at 21 andengages the longitudinally extending free edges of the ribs so as tobridge the portion of the extension member that extends beyond thedischarge outlet of the sleeve portion or nozv zle 4.

Having thus described my invention it is obvious that various immaterialmodificationsmay be made in the same without departing from the spiritof my invention; hence do not wish to be understood as limiting myselfto the exact form, construction, arrangement, and combination of partsherein shown and described, or uses mentioned, exce t as limited by theclaims.

What I c aim as new and desire to secure by Letters Patent is:

1. In a pulverized fuel and air mixer, a tubular shell, a sleeve withinsaid shell, said shell and sleeve forming a central mixing chamber forfuel and air and an air chamber surrounding one end of said mixingchamber, an inlet conduit communicating tangentially with said mixingchamber, said mixing chamber having an outlet at one end thereof, an airinlet communicatmg tangentially with said air chamber, said air chamberhaving an outlet adjacent to the said first mentioned outlet, asecondary air inlet tube extending into said mixin chamber, and meansfor controlling and directing the secondary air within the said mixingchamber.

2. In a pulverized fuel and air mixer, a tubular shell, a sleevearranged substantially co-axially within said shell, said shell andsleeve forming a mixing chamber for fuel and air and an air chamber inco-axial relation to the said mixing chamber, a closure for one end ofthe said mixing chamber and an outlet at the opposite end thereof, afuel lUO inlet conduit communicating tangentially with said mixingchamber, an air inlet conduit communicating tangentially with said airchamber, said air chamber having an outlet substantially co-axial withthe outlet ofsaid mixing chamber, a tube extending into' said mixingchamber, and means for controlling the air passing through said tubeinto said mixing chamber.

3. In a pulverized fuel and air mixer, a tubular shell and asleevewithin said shell and therewith forming a fuel and air mixing chamberand a secondary air chamber in coaxial contiguous and cooperativerelation to said first chamber, said chambers having substantiallyco-axial outlets and tangential inlets entering in opposite directions.-

4. In a pulverized fuel and air mixer, a mixing chamber for fuel andair, a closure for one'end of Said chamber, said chamber having a frustoconical wall terminating in a tubular substantially co-axial dischargeoutlet, an inlet conduit communicating tangentially with said mixingchamber, an air chamber surrounding the discharge portion of the saidmixing chamber, an air inlet conduit communicating tangentially withsaid air chamber but directed in the opposite direction to the inlet tothe fuel and air mixing chamber, said air chamber having .an outlet insubstantially co-axia1 and cooperative relation with the outlet from thesaid mixing chamber.

5. In a pulverized fuel and. air mixer, a fuel and air mixing chamberhaving a tangential inlet and a substantially co-axial outlet, an airchamber arranged substantially co-axially with the first mentionedchamber at thev outlet end thereof and in cooperative relation thereto,said air chamber being provided with an outlet substantially coaxialwith the outlet of the iirs't mentioned chamber, and air inletscommunicating with said chamber, respectively, substantiallytangentially thereto but directed in opposite directions. l

6. In a pulverized fuel and air mixer, a fuel and air mixing chamberhaving a funnel shaped extension and terminating in an outlet at one endthereof, said mixing chamber having a tangential inlet, a closure for Aone end of said mixing chamber, an air chamber surrounding the outletportion of the said mixing chamber, an air inlet communicatingtangentially with said air chamber, said air chamber being pro'videdIwith an outlet substantially co-axial with the outlet of the said mixingchamber and in cooperative relation thereto, a tube extending into thesaid mixing chamber for supplying secondary air to the fuel mixture,said tube being provided with lateral openings, and means for deflectingthe air passing through said tube into said mixingchamber.

and an air receiving chamber and terminating in an outlet opening, inletconduits, one communicating tangentially with each of said chambers,circumferentially spaced diagonal balles extending inwardly from theoutletend of said tubular shell, and an -adjustable shield lcontrollingthe passage of air between adjacent baffles.

8. In a pulverized fuel and air mixer, a tubular shell, a funnel-shapedsleeve within said shell,.said sleeve andshell forming a mixing chamberfor fuel and air and an air chamber, a fuel inlet conduit communieatingwith said mixing chamber, an outlet from said mixing chamber, an airinlet communicating tangentially with said air chamber, said air chamberhaving an outlet substantially co-axial with the outlet from theV mixingchamber, 'a tube extending longitudinally within said shell foradmitting ysecondary air to the mixing chamber, and an adjustable valveassociated with said tube for controlling the flow of air passingthrough said tube toward the outlet of said mixing chamber. j 9. In apulverized fuel and air mixer, a

tubular shell, a closure for one end -of said shell, a funnel shapedsleeve arranged substantially co-axially within said, shell separatingthe space within the shell into two chambers, inlet conduits, onecommunicating tangentially with each of @aid chambers, said chambersbeing provided with substantially co-axial contiguous outlets, a tubeextending longitudinally within the said shell for admitting secondaryair thereinto,

and a valve adjustablysupported at the end of said tube to control theflow of air there-1 through and to deflect the air current outwardly andcause it to mix with the fuel mixture passing through the surroundingchamber'. v

l0. In a pulverized fuelfand air mixer, a tubular shell, a closure for.one end of said shell, a sleeve arranged substantially co-axiallywithinsaid` shell and separating Athe space/within said shell into a mixingchamber and a secondary air chamber, inlet conduits, one communicatingtangentially with each of said chambers, said chambers havingsubstantially co-axial contiguous outlets, a tube extending through thesaid closure, substantially longitudinally and axially within said shellfor admitting secondary air, and a conical valve adj ustabliyr supportedat the end of said tube adapted to control the flow or air passing intothe surrounding chamber.

11. In a pulverized,v I'uel a-nd air mixer, a;l Y'

tubular shell, a vsleeve arranged substantially (zo-axially with saidshell, said shell and sleeve forming a central eul and air mixingchamber and an air chamber in substantially co-axial contiguous andco-operative relation to said mixing chamber, a fuel and air inletcommunicating tangentially with said mixing chamber, and an au* inletcommumeating tangentially with said air chamber, said chambers havingsubstantially co-axial outlets.

In testimony whereof, I have hereunto signed my name.

ALGOT A. WICKLAND.

